Hikvision DNS behind BT router broken email workaround

[theonetruepath 0]

Just for anyone using BT (British Telecom) as their provider that has Hikvision email suddenly broken: I was using smtp.gmail.com as my smtp mail server, it stopped working sometime between 8 May 2016 and 18 May 2016. Half a day of mucking around trying to work out what was wrong.... turns out DNS no longer works for looking up third party mail servers (in particular gmail's server) behind a BT router. Not even if you use 8.8.8.8 as your DNS - they must be using packet inspection to block it. No surprise there as they had to implement this for government-mandated blocks on other domains like torrent networks etc.

 

I switched to using an IP address directly and it is working again. Until Google change that IP on me....

 

You can't use BT's mail server because apparently they don't like Hikvision's email protocol (they want port 465, SSL and authentication in clear text with no STARTTLS, Hikvision seems to want to use only encrypted username/password).